How to create a track in Garmin Explore?

I've saved a couple of tracks in my Garmine Etrex SE and now I want to see them in Garmin Explore. In the Explore app it says 'No Tracks' and 'Use your Garmin Device to create tracks'. Well I've done that but it still says 'No Tracks'. Nothing in the SE manual of course. Is it documented anywhere? What do I have to do?